The double seal structure of the double seal plug valve is not just shown in the double disc, but more importantly, the sealing surface of each disc has both soft and hard seal types, and the precision of the hard seal is not lower than Level 4, which not only ensures the valve’s zero leakage but also makes it fireproof. As shown in Fig.l, Fig.a is the soft seal shape in the open state while Fig.b is the soft seal shape in the closed state. It can be seen from the figure that the soft seal(rubber) is embedded in the grooves of the disc, raised in the middle and concave on both sides; that is in favor of the soft seal being compressed and flowing to the grooves on both sides during the valve’s closing process to finally form a hard seal; its advantage is to protect the soft seal from being crushed and meanwhile to ensure to realize the hard seal.

The good sealing performance of the double seal plug valve can ensure the pump’s stable working state and avoid “flow cutoff for air resistance”, which has been repeatedly confirmed by our users.